1. Field of the Invention
The present invention relates to a gesture recognition apparatus for recognizing a position of a hand on a steering wheel from an image data by imaging a gesture (operation) using a steering wheel of a vehicle by an imaging device placed in the vehicle.
2. Description of the Related Art
Gesture remote-controllable operating devices using a steering wheel of a vehicle have been known wherein a driver's hand position on a steering wheel is imaged by a camera, and an operation processing is performed based on a position and a movement of the imaged hand. Gesture recognition apparatuses used in gesture remote-controllable operating devices image a driver's hand position on a steering wheel by a camera, and recognize the hand by processing the image data.
For example, Japanese Patent No. 3941786 discloses a device for outputting an operation command for on-vehicle equipments based on gestures of an operator, namely, positions and movements of his/her hand.
Japanese Unexamined Patent Application Publication No. 2007-122274 discloses a device for binarizing an image with uneven density in the background and extracting a sharper object to be detected from the binary image.
However, it is difficult to accurately read positions and movements of an operator's hand in the device disclosed in Japanese Patent No. 3941786. For example, a subtle difference in gestures made by different operators cannot be accurately recognized.
Furthermore, since the device disclosed in Japanese Unexamined Patent Application Publication No. 2007-122274 detects an object from an image with uneven density in the background, a steering wheel in the background will be free from uneven density when applied to a vehicle, and that it will be difficult to detect a position of an object, namely, a hand, from an image data imaged under an environment exposed to sunlight.
When an image data of a hand on a steering wheel imaged by a camera is binarized and the hand is recognized from the binary image, the lighted portion of the hand turns white and the non-lighted portion of the hand turns black in case that sunlight is incident from the front side of the hand, and that the hand is separated on the binary image. Also, the hand is separated on the binary image in case that the hand is lighted from the right rear side generating a lighted portion and a shaded portion on the hand. The hand may not be recognized in such cases.
Therefore, an object of the present invention is to provide a gesture recognition apparatus capable of recognizing a hand by means of a binary image regardless of direction of light contacting the hand.